US3627924A - Flat screen television system - Google Patents

Flat screen television system Download PDF

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US3627924A
US3627924A US825274A US3627924DA US3627924A US 3627924 A US3627924 A US 3627924A US 825274 A US825274 A US 825274A US 3627924D A US3627924D A US 3627924DA US 3627924 A US3627924 A US 3627924A
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light
threshold
circuit
voltage
emitting
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Gordon Ross Fleming
Kenneth E Van Landingham
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Energy Conversion Devices Inc
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Energy Conversion Devices Inc
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N3/00—Scanning details of television systems; Combination thereof with generation of supply voltages
    • H04N3/10—Scanning details of television systems; Combination thereof with generation of supply voltages by means not exclusively optical-mechanical
    • H04N3/14—Scanning details of television systems; Combination thereof with generation of supply voltages by means not exclusively optical-mechanical by means of electrically scanned solid-state devices
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/22—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources
    • G09G3/30—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2300/00—Aspects of the constitution of display devices
    • G09G2300/08—Active matrix structure, i.e. with use of active elements, inclusive of non-linear two terminal elements, in the pixels together with light emitting or modulating elements
    • G09G2300/088—Active matrix structure, i.e. with use of active elements, inclusive of non-linear two terminal elements, in the pixels together with light emitting or modulating elements using a non-linear two-terminal element
    • G09G2300/0885—Pixel comprising a non-linear two-terminal element alone in series with each display pixel element
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2300/00—Aspects of the constitution of display devices
    • G09G2300/08—Active matrix structure, i.e. with use of active elements, inclusive of non-linear two terminal elements, in the pixels together with light emitting or modulating elements
    • G09G2300/088—Active matrix structure, i.e. with use of active elements, inclusive of non-linear two terminal elements, in the pixels together with light emitting or modulating elements using a non-linear two-terminal element
    • G09G2300/089—Pixel comprising a non-linear two-terminal element in series with each display pixel element, the series comprising also other elements

Definitions

  • the electroluminescent Troy, Mich. array may include a predetermined number of row circuit lines and a predetermined number of column circuit lines arranged in a cross grid X-Y pattern to form a circuit juncture at FLATSCREEN TELEVISION SYSTEM each crossing of the column and row circuit lines, and a 11 Claims, 7 i g g threshold-operated electroluminescent circuit is connected at 521 u.s.cu. 178/7311), each iuncmres- Each electmlu' 313/108 By 315/169 TV minescent circuit, most advantageously, comprises a 51 lint. CI. n04 5/10 bidirectkma' threshold-items device having time delay 50 Field 0!
  • This invention relates generally to panel-type information display arrays, and more particularly to two-dimensional display devices for visual reproduction of electronic video signals, and to the method and apparatus for controlling such arrays.
  • this invention is directed to energizing and deenergizing a plurality of electroluminescent circuits along a given row circuit line at points in time corresponding to the amplitude of the video information to be applied at the particular discrete electroluminescent circuit along the row circuit line, and all of the electroluminescent circuits are extinguished simultaneously thus providing a gray scale for the electroluminescent array to display rapidly changing video signal information therefrom.
  • the electroluminescent element must be controlled in accordance with the stored video signal information; and the switching device used to control the electroluminescent element must exhibit a welldefined threshold voltage value. The tolerance to the threshold voltage value of a multitude of threshold-switching devices must be very close. in addition, the electroluminescent elements must exhibit low power consumption, and must be capable of batch fabrication in geometrics that can be assembled into display panels.
  • a common type of construction for an electroluminescent display panel is the cross grid or X-Y type.
  • the parallel placed electrodes of this type of construction are divided into strips and oriented at right angles to each other.
  • Such panels generally display a cartesian coordinate system, the may, if desired, display a polar coordinate system or and other system desired.
  • an alternating current voltage is applied between the selected X and Y cross grids to energize the electroluminescent element at the juncture thereof.
  • X- Y display panels of this type possess many such junctures each of which constitutes a connection means for a picture element to form a point on the electroluminescent array. Energizing selected picture elements would malre possible the display of television pictures, or other information patterns or numbers.
  • this invention provides means to energize a complete row of electroluminescent elements by applying operating potential to the selected row circuit line while each column circuit line receives video signal information which will energize the electroluminescent circuits along the selected row circuit lines at different points in time to emit different amounts of light intensity from the discrete picture elements along the row circuit line, and the operating POTEN- TlAL applied to the selected row circuit line is removed therefrom simultaneously to deenergize all the picture ele ments therealong.
  • the next row circuit line is then energized and video information applied thereto, and this process is re peated as line at a time ultimately completely to form a display pattern.
  • the switching devices used in this invention are one layer type threshold semiconductor devices each having substantially identically conduction characteristics for positive and negative applied voltages but which may have slightly different threshold voltage values with respect to one another.
  • the threshold-switching devices initially presents a very high rmiatance in response to an applied voltage of either polarity below and upper threshold level and in response to an applied voltage of either polarity above the upper threshold level, changes a high to a low resistance condition, such change occuring after an inherent time delay of the threshold switching devices but once switching is established it is substantially instantaneous.
  • the thrwhold semiconductor switching devices automatically reset themselves to their high resistance state when the current therethrough drops below a minimum holding current value which is near zero.
  • the threshold-switching devices have a substantially reduced threshold voltage value immediately after they are rendered nonconductive, and after a relatively short recovery delay time, during which the threshold voltage value progressively increases, the normal initial threshold voltage value is again reached.
  • Semiconductor materials used to form such threshold-switching devices most advantageously are of the type disclosed in US. Pat. No. 3,271,591 issued to Standford R. Ovshinsky and sometimes referred to therein as mechanism devices without memory.”
  • an inherent characteristic of particular importance is that of a varying time delay between the time a threshold voltage is applied to the threshold-switching device and the time the thresholdswitching device actually changes from its high resistance blocking condition to its low resistance conducting condition, but when switching occurred it is substantially instantaneous, as for example in the order of nanoseconds.
  • the turn-on time delay of these devices will vary with changes in applied voltage in excess of the threshold voltage value of the particular devices involved, and increase in voltage from the threshold voltage value to a greater voltage causing a decrease in the inherent turn-on time delay.
  • the threshold-switching device will not be rendered conductive.
  • an amplituderesponse signal is applied to the threshold-switching device, the inherent time delay of the switching device will cause it to be rendered conductive at a point in time determined by the amplitude of the applied signal.
  • alternating current voltage is applied to the threshold switching devices used in this invention, and which alternating current voltage is of a sufficiently high frequency so that periodic pulses of the applied frequency have a time duration less than the inherent time delay corresponding to the amplitude of the applied voltage then a voltage value in excess of the threshold voltage value of the thresholdswitching device may be applied thereto without rendering the switching device conductive.
  • Yet another inherent characteristic of the thresholdswitching devices most advantageously used in this invention is that of the inherent recovery time delay of the threshold voltage value back to the original or normal threshold voltage value after the switching devices are turned off as a result of decreasing currents therethrough below the minimum holding current. That is, there will exist a substantially diminished threshold voltage value after the switching devices are turned of and which will increase with increasing time back to the original or normal threshold voltage value. Therefore, if a pulse or voltage is applied to any one of the thresholdswitching devices within the recovery time delay period after it is rendered nonconductive, this pulse need only have an amplitude equal to the then existing threshold voltage value to again render the threshold-switching device conductive.
  • the operating potential applied to the threshold-switching devices is an alternating current voltage of sufficient frequency so that each successive periodic pulse of the applied potential will occur within the inherent time delay for full recovery of the switching device, these switching devices will be continuously rendered conductive on each half cycle of the applied voltage even if the applied voltage is substantially below the normal or initial threshold voltage value of the threshold switching devices involved.
  • FIG. 1 is a simplified block diagram of an electrolu minescent display system constructed and operated in accordance with this invention
  • FIG. 2 is a schematic diagram illustrating the circuit components of an electroluminescent circuit which is used at each picture element of the electroluminescent array of this invention
  • FIG. 3 is a voltage current characteristic of the thresholdswitching device used in this invention.
  • FIG. 4 is a graphic representation of the inherent tum-on time delay of the threshold-switching device used in this invention.
  • FIG. 5 is a graphic representation of the inherent recovery time delay of the threshold-switching device used in this invention.
  • FIG. 5A is a graphic representation of the frequency versus threshold voltage value of its threshold-switching device used in this invention.
  • FIG. 6 is a series of waveforms illustrating the operation of a plurality of electroluminescent circuits along a given row circuit line of an X-Y electroluminescent array to establish the desired variations in light intensity from each electroluminescent circuit along the selected row to provide a gray scale for the display pattern formed by the apparatus of FIG. 1.
  • a control circuit is designated generally by reference numeral 10 to operate a cross grid X-Y electroluminescent array 12 in response to a video signal information receiver 14.
  • the video signal information receiver 114 may be a conventional television receiver to provide the appropriate video signal information and synchronizing pulse signal information to operate a plurality of electroluminescent circuits 16 along a given one of a plurality of row circuit lines 17, 18, 19, 20, and 21 one line at a time.
  • the video signal information is applied to a plurality of column circuit lines 22, 23, 24, 25, 26,
  • each electroluminescent circuit will be energized to a period of time corresponding to the amplitude or relative brightness of the signal to be displayed.
  • a gated oscillator 28 which receives synchronizing signals from the video signal information receiver 14 via a line 29 to operate the gated oscillator 28 in such a manner as to sequentially energize the lines 17-21 at a speed corresponding to the vertical sweep speed, as for example, of a television set.
  • a video signal information converter and parallel output circuit 30 receives video signal information from the video signal information receiver 14 via a video line 31 and converts the serial input of the video information to a parallel output, this being accomplished by any suitable well-known means for serial to parallel conversion.
  • a synchronizing pulse via a line 32 will apply the stored video information simultaneously or substantially simultaneously to all of the electroluminescent circuits 16 along a given selected row, as for example the row circuit line 17.
  • Each of the electroluminescent elements 16 along the row circuit line 17 is rendered operative at a different point in time during which the operating potential is applied to the row circuit line 17, the electroluminescent elements being energized for the longest period of time emitting the brightest light and the electroluminescent elements energized for the shortest period of time and emitting the least amount of light and a plurality of variation therebetween thus forming a gray scale for a given picture line to be displayed.
  • the electroluminescent circuit 16 includes a resistor 35 connected to a voltage amplitude and time delay threshold-switching device 36, which, in turn, is connected to an electroluminescent element 37.
  • an electroluminescent element 37 acts as a capacitator in the circuit, and when the threshold-switching device 36 is rendered conductive charge is applied to the electrode 37a.
  • the electroluminescent circuit is a bistable circuit remaining in its table off condition until the threshold-switching device 36 is initially rendered conductive
  • the electroluminescent circuit will remain in a stable on condiction as long as voltage is applied to the juncture of the electrodes l7 and Fill.
  • the inherent recovery time delay of the thresholdswitching device it increases the bistable range of the electroluminescent circuit beyond that which is normally obtainable with capacitive reactive bistable circuits.
  • NUS. 3, d, Ll and do which illustrate the various electrical characteristics of the threshold-switching device FM.
  • the thresholdswitching device lid is symmetrical in its operation, blocking current substantially equally in each direction and conducting current substantially equally in each direction, and the switching between the blocking and conducting condition being extremely rapid after the inherent time delay.
  • lFlG. El is an l-V curve illustrating the AC operation oil the thresholdswitching device 1%, it being understood that either the first or third quadrant alone will represent the application of a direct current voltage (DC).
  • DC direct current voltage
  • the threshold-switching device 3b is normally in its high resistance blocking condition, and, as the DC voltage is increased, the voltage current characteristics of the device are illustrated by the curve ill, the electrical resistance oi the device being high and substantially blocldng current flow therethrough.
  • the high electrical resistance of the semiconductor materials substantially instantaneously decreases in at least one path through the semiconductor material forming the threshold-switching device Ill: to a low electrical resistance, the substantially instantaneous switching occurring after the inherent time delay as indicated by the curve ll.
  • This provides a low electrical resistance conducting condition for conducting current thcrethrough.
  • the low electrical resistance is many orders of magnitude less than the high electrical resistance.
  • the conducting condition is illustrated by the curve M and it is noted that there is a substantially linear current characteristic and substantially constant voltage characteristic which is the same for increases and decreases in current. in other words, current is conducted at a substantially constant voltage.
  • the low resistance condition of the semiconductor material forming the thresholdswitching device Elli has a voltage drop which is a minor fraction of the voltage-drop in the high resistance blocking condition.
  • the threshold voltage value of the threshold-switching device is substantially reduced immediately after the threshold-switching device is rendered nonconductive and the threshold voltage value in creases to the normal initial threshold voltage after a predetermined recovery time delay.
  • the l-V curve is illustrated by quadrants l and El of the l lfi. 3.
  • the threshold-switching device lid is in its blocking condition when the peak value of the applied alternating current voltage is below the threshold voltage value oi the device.
  • the blocking condition being illustrated by the curves illill in both quadrants l and 3.
  • the device is substantially instantaneously switched along the curves illll. ll to the conducting condition illustrated by the curves dill-d2, the
  • the device switching during each half cycle of the applied alternating current voltage. As the applied alternating current voltage nears aero so that the current through the threshold-switching device llti falls below the minimum holding current value, the device switches along the curves ss-as from the low electrical resistance condition to the high electrical resistance condition to the high electrical resistance condition illustrated by the curves sill-dill, this switching occuring near the end of each half of the cycle.
  • the threshold-switching device 36 has an inherent time delay between the time the threshold voltage is applied thereto and the time the switching device is actually rendered conductive, and this time is inversely proportional to the amount of overvoltage applied to the threshold-switching device, as illustrated by the curve 35.
  • the values of the inherent time delay and the threshold voltage may be altered by, among other things, changing the composition of the semiconductor material used in forming the threshold-switching device 345 or by varying the thickness of the layer or film forming the thresholdswitching device.
  • the time delay T will decrease with increases of applied voltage between the V and V Therefore, the time duration of the applied voltage on the thresholdswitching device 36 need only be as long as the time delay corresponding to the time delay of the voltage value in excess of V lFlG. 5 illustrates the inherent recovery time delay 1",, of the threshold-switching device 36 to recover to its normal threshold voltage value after the threshold-switching device is rendered nonconductive, this being indicated by the curve 46.
  • the threshold switching device 36 immediately after the threshold switching device 36 is rendered nonconductive it will have a substantially reduced threshold voltage value which increases with time until the normal threshold value V, is again reached, the time delays being readily selected by, among other things, varying the composition of the material used to form the threshold-switching device as. if the threshold-switching device as is operated by a series of voltage pulses, as, for example, alternating current voltage or pulsating direct current voltage, only an initial voltage pulse need have a voltage amplitude and time duration corresponding to the initial threshold voltage value and time delay as illustrated in FIG. 4, or a lesser time delay corresponding to the the overvoltage of the applied. pulse.
  • this subsequent pulse voltage need only have an amplitude equal to the then existing threshold voltage value, which may be, for example, any where between 0.01V to V,- depending upon the point in time the next pulse of voltage is applied.
  • the turn on time delay illustrated in FIG. 4 may persist regardless of the time at which the subsequent pulse of voltage is applied to the threshold-switching device Elli the only difference being a decrease or shifting of the entire curve All; as indicated by the family of curves shown in broken lines at Ma.
  • the threshold-switching device once the threshold-switching device is rendered conductive, it can be successively rendered conductive by closely spaced pulses which have voltage amplitudes less than the initial normal threshold voltage value of the switching device. However, if the applied voltage, whether direct current or alternating current pulses, is extinguished for the time interval at corresponding to the inherent recovery time delay of H6. 5, the threshold-switching device 36 will fully recover to its initial normal threshold voltage value and no longer will be rendered conductive as a result of a continuously applied voltage having an amplitude below the threshold voltage value of the threshold-switching device.
  • FIG. A the threshold voltage value versus frequency characteristic of the threshold-switching device 36 is illustrated by a curve 47. Because of the inherent recovery time delay of the threshold-switching device 36, the thresholdswitching device will operate within a bistable operating range, regardless of the type of load or circuit arrangement to which it is connected. Therefore, when the thresholdswitching device 36 is used in conjunction with a capacitive reactive circuit which also has a bistable operating range, the combined bistable characteristics of the capacitive reactive device, here being an electroluminescent element, and the bistable operating range of the threshold-switching device combine to form a substantially increased bistable operating range with an increase in frequency.
  • the amount of increase of the bistable range of an electroluminescent circuit of this invention increases in accordance with an increase in the differential between the initial normal threshold voltage value and the then existing threshold voltage value. This is indicated by the increase in vertical spacing between the extended broken line at the value V and the curve 47, of FIG. 5A.
  • the electroluminescent array 12, of FIG. 1 can be operated in a novel and unique manner.
  • a continuously applied operating potential which may be considered a packet, either of AC or DC voltage, is sequentially applied to the row circuit lines 17-21.
  • the row circuit line 17 has applied thereto the alternating current voltage 50, of FIG. 6, and none of the electroluminescent circuits 16 along the row circuit line 17 will be energized.
  • video signal pulse is applied to each of the column circuit lines 22-27 the electroluminescent circuit across the junctures will be rendered operative response to a time delay corresponding to the amount of video information to be displayed.
  • each of the electroluminescent circuits 16 can be divided into equal brightness intervals or levels, indicated by B,-l3, Fig. 6, the application of a video pulse at any one of these intervals will determine the amount of brightness obtained by the electroluminescent circuit, at the juncture of the row circuit line 17 and any given one of the plurality of column circuit lines 22-27. Therefore, when a video pulse 52 is applied to a selected one of the column circuit lines 22-27, for example, during the interval 3,, the brightness of the selected electroluminescent circuit 16 will be seven-tenths of the total brightness obtainable by the application of all the pulses within the wave packet containing the sine wave pulses 50.
  • the voltage variation across the electroluminescent element is substantially an AC voltage varying about a zero reference line 54.
  • the voltage variation is across the entire electroluminescent circuit may be a varying direct current voltage because of a combination of the applied alternating current voltage to the line 17 and the video pulse applied to any one of the lines 22-27, as illustrated by the varying direct current voltage 50a.
  • the light emitted from the electroluminescent circuit 16 is reduced so as to emit five-tenths of the total light output of the electroluminescent element during the interval when both an operating potential and a video signal are applied to the selected circuit lines.
  • the minimum amount of light obtainable from any given electroluminescent circuit 16 will be that represented by the brightness level B which allows only a single pulse of altemating current voltage to be applied to the electroluminescent element 37.
  • the maximum amount of the 70 brightness obtainable from a selected electroluminescent element 37 is achieved by applying a video pulse to a selected one of the column circuit lines 22-27 at the same time the applied operating potential is applied to the selected row circuit wave packet, is used to energize the electroluminescent element 37. Therefore, by operating the electroluminescent array 12 in accordance with the method disclosed herein and illustrated in FIG. 6, a plurality of different light intensities is obtainable from each of the electroluminescent circuits 16 depending on the point in time the video signal information is applied to the vertical column circuit lines 22-27 while a selected one of the row circuit lines 17-21 has operating potential applied thereto.
  • the row circuit lines 17-21 are sequentially scanned one after the other either from top to bottom or from bottom to top to provide the line-at-a-time scanning of the entire electroluminescent array 12, thereby allowing an entire frame of video display pattern to be formed.
  • the gated oscillator then operates To apply an operating potential to a selected row circuit line, for example, row circuit line 17, for a time duration corresponding to the sweep time duration of a conventional television receiver.
  • the time duration between pulses may be selected to be within the inherent recovery time delay of the threshold-switching device 36.
  • the threshold-switching device 36 acts basically as an isolation device to isolate all picture elements from being energized until the appropriate video pulse is applied thereto after which time all the pulses remaining within the packet of operating potential will be applied to the electroluminescent element 37 without further consideration of the initial normal threshold voltage value of the threshold-switching device 36.
  • each of the electroluminescent elements By selecting the points in time at which each of the electroluminescent circuits along a selected row circuit line is energized, and by terminating energization of all the electroluminescent circuits simultaneously when shifting the operating potential from one line to the next, each of the electroluminescent elements will emit different amounts of light thus forming the gray scale necessary to display television pictures on a flat screen electroluminescent array.
  • the simultaneous termination of energization of all the electroluminescent circuits on a given row circuit line in accordance with this invention, is a straightforward method of compensating for the inherent recovery delay of the threshold-switching devices since a given row circuit line is energized with operating potential only one during each frame of video information displayed.
  • threshold switching devices having the electrical characteristics disclosed herein, in combination with an electroluminescent circuit arrangement wherein the electroliminescent element thereof acts as a capacitor, and by operating a plurality of such electroluminescent circuits in accordance with this invention, a plurality of different light intensities are obtainable to establish a gray scale substantially corresponding to the gray scale of the video information to be displayed.
  • the method of controlling energization of discrete points on a display array according to claim 1 further including the step of converting said video signal information from amplitude signal information to pulse width signal information applied to said column circuit lines and corresponding in time duration to the amplitude of the video signal information, thus energizing selected ones of said light-emitting elements for periods of time corresponding to the relative brightness of the video signal information involved.
  • each light control and emitting circuit connected across each pair of junctures of said row and column circuit lines has at least one circuit component which has inherent time delay characteristics to provide a time delay which is a function of the amplitude of the video signal information involved.
  • each of said switch means of each light control and emitting circuit is a voltage amplitude threshold switching means having a threshold voltage value which when exceeded by an applied voltage drives the same into a conductive state until current is interrupted therethrough, each of said threshold-switching means connected in series with a different one of the said light-emitting elements of said array, said threshold-switching means have an inherent turn-on time delay between the time a voltage in excess of the threshold voltage value of said threshold-switching means is applied thereto and the time said threshold-switching means is rendered conductive and an inherent recovery time delay between the time said thresholdswitching means is rendered nonconductive and the time that said threshold-switching means recovers to its initial normal threshold voltage value, the threshold voltage value thereof immediately after said threshold-switching means is rendered nonconductive being substantially less than the said initial normal threshold voltage value and progressively increasing to said initial normal threshold voltage value, said operating potential applied to said selected row circuit line being below said initial normal normal
  • a method for controlling energization of discrete points on a display array of the type having row and column circuit lines respectively having pairs of circuit junctures therealong, a light control and emitting circuit across each pair of said junctures, and each of said light control and emitting circuits including a light-emitting element connected in circuit with a voltage amplitude responsive threshold-switching means which is initially rendered operative at a predetermined threshold voltage value comprising the steps of: applying an operating potential for energizing said light-emitting element simultaneously to all the light control and emitting circuits along a selected row circuit line, said operating potential being below at least an initial threshold voltage value of said threshold-switching means; applying to said column circuit lines video signal controlled information having a voltage amplitude which when combined with the continuously applied operating potential is sufficient to energize the light control and emitting circuits at the junctures along the said selected row circuit line for a period of time corresponding to the light intensity of the video signal information to be displayed; and removing said operation potential from the
  • a circuit arrangement for controlling energization of a display array comprising: a first group of circuit lines and a second group of circuit lines, each of said first and second group of circuit lines arranged with respect to one another to form respective pairs of circuit junctures corresponding in number to the number of discrete points on a display array; a light control and emitting circuit connected between each of said pair of junctures formed by said first and second group of circuit lines, each of said light control and emitting circuits including a light-emitting element and threshold-switching means connected in a circuit with said light-emitting element, said threshold-switching means being rendered conductive a predetermined threshold voltage value after an inherent tumon time delay to operatively energize the light-emitting element associated therewith; means for applying to selective ones of said first group of the circuit lines an operating potential below the threshold voltage value of said thresholdswitching means of each of said light control and emitting circuits; means for applying video signal controlled voltages to each of the circuit lines in said the second group of
  • circuit arrangement for controlling energization of a display array further including means for delaying of said video signal controlled voltages for a period which is a function of the amplitude of the video signal information.
  • a method for controlling the energization of a light control and emitting circuit including a light-emitting element which is connected in series with a voltage amplitude responsive thresholdswitching means initially rendered operative at a predetermined threshold voltage value comprising the steps of: cyclically applying to said light control and emitting circuit a pulsating voltage waveform of a predetermined number of pulses unrelated to the particular desired intensity of the light 12 to be emitted by the light-emitting emitting element and having amplitudes below at least an initial threshold voltage value of the associated threshold-switching means; and superimposing on said pulsating operating potential a light intensity controlling voltage having a characteristic which varies with the desired intensity of the light to be emitted by said lightemitting element and which, when combined with a pulse of said pulsating voltage wavefonn, is sufficient to produce across the associated threshold-switching means a resultant voltage exceeding said initial threshold voltage value, the superpositioning on said pulsating voltage waveform on said light intensity controlling voltage
  • a light control and emitting circuit comprising: a lightemitting element; voltage-responsive, threshold-switching means which is normally in a nonconductive state and switches to a conductive state when a voltage of at least a given threshold voltage value is applied thereacross and reverts to a nonconductive state when the current therethrough drops below a given minimum holding current value; a source of energizing voltage which cyclically provides during various given periods a pulsating voltage waveform of a predetermined number of pulses unrelated to the particular desired intensity of the light to be emitted by the light-emitting element and having amplitudes below at least an initial threshold voltage value of the associated threshold-switching means; a source of a light intensity controlling voltage having a characteristic which varies with the desired intensity of the light to be emitted by said light-emitting element and which, when combined with a pulse of said pulsating voltage wavefonn, is sufficient to produce across the associated threshold-switching means a resultant voltage exceeding said initial threshold voltage
  • a light control and emitting circuit comprising: a lightemitting element; a source of energizing voltage which repeatedly produces over various given periods a pulsating voltage waveform of a predetermined number of pulses unrelated to the particular desired intensity of the light to be emitted by the light-emitting element; a source of light intensity controlling voltage having a characteristic which varies with the desired intensity of the light to be emitted by said lightemitting element; and circuit-forming forming means interconnecting said source of energizing voltage, said source of said light intensity controlling voltage and said light-emitting

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  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Control Of Indicators Other Than Cathode Ray Tubes (AREA)
  • Electroluminescent Light Sources (AREA)
  • Transforming Electric Information Into Light Information (AREA)
US825274A 1969-05-16 1969-05-16 Flat screen television system Expired - Lifetime US3627924A (en)

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US82527469A 1969-05-16 1969-05-16

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DE (1) DE2023692B2 (fr)
FR (1) FR2047858A5 (fr)
GB (1) GB1319301A (fr)
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Cited By (31)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3742483A (en) * 1971-06-01 1973-06-26 Burroughs Corp Video display system using display panel
US3765011A (en) * 1971-06-10 1973-10-09 Zenith Radio Corp Flat panel image display
US3801861A (en) * 1971-10-12 1974-04-02 Owens Illinois Inc Drive waveform for gas discharge display/memory panel
US3809952A (en) * 1971-06-21 1974-05-07 Burroughs Corp Apparatus reducing the power required for scanned display devices
US3863023A (en) * 1973-02-28 1975-01-28 Owens Illinois Inc Method and apparatus for generation of gray scale in gaseous discharge panel using multiple memory planes
US3886403A (en) * 1971-12-30 1975-05-27 Fujitsu Ltd Brightness modulation system for a plasma display device
US4009335A (en) * 1973-08-09 1977-02-22 Stewart-Warner Corporation Gray scale display system employing digital encoding
US4020280A (en) * 1973-02-21 1977-04-26 Ryuichi Kaneko Pulse width luminance modulation system for a DC gas discharge display panel
US4021607A (en) * 1973-05-19 1977-05-03 Sony Corporation Video display system employing drive pulse of variable amplitude and width
US4024529A (en) * 1974-06-11 1977-05-17 Nippon Hoso Kyokai Image display device
US4074319A (en) * 1976-12-13 1978-02-14 Bell Telephone Laboratories, Incorporated Light emitting diode array imaging system - parallel approach
FR2382733A1 (fr) * 1977-03-03 1978-09-29 Westinghouse Electric Corp Dispositif d'affichage electro-optique
US4193095A (en) * 1977-02-25 1980-03-11 Hitachi, Ltd. Driver system of memory type gray-scale display panel
DE3015887A1 (de) 1979-04-25 1980-11-06 Hitachi Ltd Serien-parallel-signalumsetzer
US4323896A (en) * 1980-11-13 1982-04-06 Stewart-Warner Corporation High resolution video display system
US4344622A (en) * 1978-06-16 1982-08-17 Rockwell International Corporation Display apparatus for electronic games
DE3049666C2 (de) * 1979-04-25 1983-12-08 Hitachi Ltd Zeilenspeicher
US4447812A (en) * 1981-06-04 1984-05-08 Sony Corporation Liquid crystal matrix display device
EP0181174A2 (fr) * 1984-11-05 1986-05-14 Kabushiki Kaisha Toshiba Dispositif d'affichage à adressage matriciel
FR2584520A1 (fr) * 1985-07-03 1987-01-09 Sayag Electronic Dispositif d'affichage comportant un reseau matriciel de sources lumineuses
US4646079A (en) * 1984-09-12 1987-02-24 Cornell Research Foundation, Inc. Self-scanning electroluminescent display
US4652872A (en) * 1983-07-07 1987-03-24 Nec Kansai, Ltd. Matrix display panel driving system
US4662720A (en) * 1983-03-30 1987-05-05 Manchester R & D Partnership Colored encapsulated liquid crystal devices using imbibition of colored dyes and scanned multicolor displays
US4834508A (en) * 1985-03-01 1989-05-30 Manchester R & D Partnership Complementary color liquid crystal display
US4878741A (en) * 1986-09-10 1989-11-07 Manchester R & D Partnership Liquid crystal color display and method
US4953953A (en) * 1985-03-01 1990-09-04 Manchester R & D Partnership Complementary color liquid display
US5142389A (en) * 1985-03-01 1992-08-25 Manchester R & D Limited Partnership Liquid crystal color display and method
US5168380A (en) * 1985-03-01 1992-12-01 Manchester R & D Partnership An Ohio Limited Partnership Multiple containment mediums of operationally nematic liquid crystal responsive to a prescribed input
US5208686A (en) * 1985-03-01 1993-05-04 Manchester R&D Partnership Liquid crystal color display and method
US5345322A (en) * 1985-03-01 1994-09-06 Manchester R&D Limited Partnership Complementary color liquid crystal display
US20040008074A1 (en) * 2001-08-22 2004-01-15 Satoshi Takehara Display panel drive circuit

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS546421A (en) * 1977-06-16 1979-01-18 Sony Corp Picture display unit

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US3021387A (en) * 1956-04-13 1962-02-13 Rca Corp Electrical display device
US3254267A (en) * 1960-10-25 1966-05-31 Westinghouse Electric Corp Semiconductor-controlled, direct current responsive electroluminescent phosphors
US3290554A (en) * 1962-12-17 1966-12-06 Edgar A Sack Electroluminescent display screen and circuit therefor
US3340405A (en) * 1966-07-05 1967-09-05 Energy Conversion Devices Inc Alternating current phase control circuit
US3526711A (en) * 1966-09-30 1970-09-01 Philips Corp Device comprising a display panel having a plurality of crossed conductors driven by an amplitude to pulse width converter

Patent Citations (5)

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Publication number Priority date Publication date Assignee Title
US3021387A (en) * 1956-04-13 1962-02-13 Rca Corp Electrical display device
US3254267A (en) * 1960-10-25 1966-05-31 Westinghouse Electric Corp Semiconductor-controlled, direct current responsive electroluminescent phosphors
US3290554A (en) * 1962-12-17 1966-12-06 Edgar A Sack Electroluminescent display screen and circuit therefor
US3340405A (en) * 1966-07-05 1967-09-05 Energy Conversion Devices Inc Alternating current phase control circuit
US3526711A (en) * 1966-09-30 1970-09-01 Philips Corp Device comprising a display panel having a plurality of crossed conductors driven by an amplitude to pulse width converter

Cited By (34)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3742483A (en) * 1971-06-01 1973-06-26 Burroughs Corp Video display system using display panel
US3765011A (en) * 1971-06-10 1973-10-09 Zenith Radio Corp Flat panel image display
US3809952A (en) * 1971-06-21 1974-05-07 Burroughs Corp Apparatus reducing the power required for scanned display devices
US3801861A (en) * 1971-10-12 1974-04-02 Owens Illinois Inc Drive waveform for gas discharge display/memory panel
US3886403A (en) * 1971-12-30 1975-05-27 Fujitsu Ltd Brightness modulation system for a plasma display device
US4020280A (en) * 1973-02-21 1977-04-26 Ryuichi Kaneko Pulse width luminance modulation system for a DC gas discharge display panel
US3863023A (en) * 1973-02-28 1975-01-28 Owens Illinois Inc Method and apparatus for generation of gray scale in gaseous discharge panel using multiple memory planes
US4021607A (en) * 1973-05-19 1977-05-03 Sony Corporation Video display system employing drive pulse of variable amplitude and width
US4009335A (en) * 1973-08-09 1977-02-22 Stewart-Warner Corporation Gray scale display system employing digital encoding
US4024529A (en) * 1974-06-11 1977-05-17 Nippon Hoso Kyokai Image display device
US4074319A (en) * 1976-12-13 1978-02-14 Bell Telephone Laboratories, Incorporated Light emitting diode array imaging system - parallel approach
US4193095A (en) * 1977-02-25 1980-03-11 Hitachi, Ltd. Driver system of memory type gray-scale display panel
FR2382733A1 (fr) * 1977-03-03 1978-09-29 Westinghouse Electric Corp Dispositif d'affichage electro-optique
US4344622A (en) * 1978-06-16 1982-08-17 Rockwell International Corporation Display apparatus for electronic games
DE3049666C2 (de) * 1979-04-25 1983-12-08 Hitachi Ltd Zeilenspeicher
DE3015887A1 (de) 1979-04-25 1980-11-06 Hitachi Ltd Serien-parallel-signalumsetzer
US4323896A (en) * 1980-11-13 1982-04-06 Stewart-Warner Corporation High resolution video display system
US4447812A (en) * 1981-06-04 1984-05-08 Sony Corporation Liquid crystal matrix display device
US4662720A (en) * 1983-03-30 1987-05-05 Manchester R & D Partnership Colored encapsulated liquid crystal devices using imbibition of colored dyes and scanned multicolor displays
US4652872A (en) * 1983-07-07 1987-03-24 Nec Kansai, Ltd. Matrix display panel driving system
US4646079A (en) * 1984-09-12 1987-02-24 Cornell Research Foundation, Inc. Self-scanning electroluminescent display
US4758831A (en) * 1984-11-05 1988-07-19 Kabushiki Kaisha Toshiba Matrix-addressed display device
EP0181174A2 (fr) * 1984-11-05 1986-05-14 Kabushiki Kaisha Toshiba Dispositif d'affichage à adressage matriciel
EP0181174A3 (en) * 1984-11-05 1987-07-01 Kabushiki Kaisha Toshiba A matrix-addressed display device
US4953953A (en) * 1985-03-01 1990-09-04 Manchester R & D Partnership Complementary color liquid display
US4834508A (en) * 1985-03-01 1989-05-30 Manchester R & D Partnership Complementary color liquid crystal display
US5142389A (en) * 1985-03-01 1992-08-25 Manchester R & D Limited Partnership Liquid crystal color display and method
US5168380A (en) * 1985-03-01 1992-12-01 Manchester R & D Partnership An Ohio Limited Partnership Multiple containment mediums of operationally nematic liquid crystal responsive to a prescribed input
US5208686A (en) * 1985-03-01 1993-05-04 Manchester R&D Partnership Liquid crystal color display and method
US5345322A (en) * 1985-03-01 1994-09-06 Manchester R&D Limited Partnership Complementary color liquid crystal display
FR2584520A1 (fr) * 1985-07-03 1987-01-09 Sayag Electronic Dispositif d'affichage comportant un reseau matriciel de sources lumineuses
US4878741A (en) * 1986-09-10 1989-11-07 Manchester R & D Partnership Liquid crystal color display and method
US20040008074A1 (en) * 2001-08-22 2004-01-15 Satoshi Takehara Display panel drive circuit
US7233322B2 (en) * 2001-08-22 2007-06-19 Asahi Kasei Microsystems Co., Ltd. Display panel drive circuit

Also Published As

Publication number Publication date
CA928824A (en) 1973-06-19
DE2023692A1 (de) 1970-11-19
DE2023692B2 (de) 1975-03-13
FR2047858A5 (fr) 1971-03-12
NL7007096A (fr) 1970-11-18
DE2023692C3 (fr) 1975-10-09
SE364162B (fr) 1974-02-11
GB1319301A (en) 1973-06-06

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